甘肃大水金矿床方解石的稀土元素地球化学特征

方解石是大水金矿床脉石矿物之一,其形成贯穿整个成矿过程。根据野外观察和室内分析,大水金矿床中的方解石分为矿化期前、矿化期和矿化期后3期。通过对不同产出类型方解石稀土元素地球化学特征研究表明：不同产出类型的方解石稀土元素含量、有关参数和配分模式均有不同程度的差别,显示不同来源;矿床成矿流体具多来源特征。成矿环境表现为相对开放而氧化的环境。     

云南金平长安金矿床稀土元素特征及其地质意义

通过长安金矿床不同类型矿石、岩浆岩和白云岩地层稀土元素地球化学对比研究,结合显微镜蚀变矿化特征观察,对该矿床与不同类型地质体成因关系进行讨论。石英正长斑岩、正长斑岩、正长岩、煌斑岩、辉绿岩稀土配分曲线均为右倾型,配分模式相似,指示矿区内三类长英质岩石和中基性煌斑岩、辉绿岩可能为同源岩浆演化产物。毒砂矿化原生矿石与弱黄铁矿化原生矿石相比,Eu负异常程度低,而矿区内煌斑岩与辉绿岩具有弱负Eu异常,指示毒砂矿化作用可能与煌斑岩与辉绿岩岩浆活动有关。黄铁矿化白云岩比无蚀变白云岩稀土元素总量（∑REE）要高,但两者稀土配分模式基本一致,指示黄铁矿化成矿热液稀土元素特征与白云岩稀土元素特征相似,推断黄铁矿化热液可能来源于白云岩变质热液。     

甘肃枣子沟金矿床稀土元素地球化学特征

对比研究了枣子沟金矿区内不同类型矿石与成矿有关的岩浆岩及地层的稀土元素地球化学特征,借以示踪成矿物质来源。研究表明,矿床不同类型矿石的稀土元素配分曲线既有相似又有差别,反映成矿物质具有多样性;矿石与容矿岩石（地层、岩浆岩）稀土元素配分曲线颇为相似,总体呈右倾型,具Eu负异常。表明成矿与容矿岩石（地层、岩浆岩）具有一定的成因联系。成矿物质来源于壳源及壳幔混合。地幔流体可能参与了矿床成矿作用。成矿环境表现为早期还原,晚期由还原向氧化转化。     

Geochemical characteristics and significance of major elements,trace elements and REE of NM copper polymetal deposit in Laos

The NM copper polymetal deposit is located in the middle north part of the Truong Son metallogenic belt in Laos,which is the skarn-typed deposit and located in the contact between Indosinian granite and Lower Carboniferous limestone.All the ore-bodies in NM deposit can be divided into four types according to their occurrences:I copper ore-body as the massive restite developed in inner contact near the granite in north part;Ⅱ-1 zinc-copper ore body and Ⅱ-2 copper-iron ore body developed within contact betwee...     

Rare earth element geochemical constrains on metallogeny of Jiapigou gold belt, Northeast China

Analyses of rare earth elements (REE) in gold-bearing quartz vein, granite and altered wall-rock (amphibolite) collected from Jiapigou gold belt in Southeast Jilin Province were conducted using inductively coupled plasma-mass-spectrometry (ICP-MS). The results in- dicated that the Jiapigou gold belt underwent two periods of gold mineralization: the earlier mineralization was related to the intrusion of Neoarchaean kaligranite, where the REE of earlier gold-bearing quartz veins and Neoarchaean kaligranites were typically featured by lower concentration and positive Eu anomaly; the later mineralization was related to the intrusion of the Yanshanian granite in Mesozoic, where the REE of later gold-bearing quartz veins and Yanshanian granites were typically featured by high concentration and negative Eu anomaly. However, the metallogenic mechanisms of the earlier and of the later gold mineralization periods were analogous, metallogenic materials were heterogenous with metallogenic fluids which mainly originated from magmatic hydrothermal fluids, mixed with metamorphic fluids; the metallogenic materials were mainly derived from the altered wall rock.     

陕西凤县温江寺锑—金矿床地质特征

秦岭造山带三叠系中的微细浸染型金矿多年来未得到突破,陕西凤县温江寺金矿的发现给本区微细浸染型金矿找矿带来契机,研究区该金矿带已控制长约10 km,温江寺金矿赋存在下三叠统任家沟组粉砂细砂岩—粉砂质泥板岩—碳质泥板岩—碳质泥灰岩—薄层灰岩薄互层中,沉积成岩黄铁矿莓球含As 0.5%。早燕山期斑状斜长花岗岩脉顺层侵入该含矿沉积层中,为成矿带入Mo-Bi-Te相关组分。晚期递进性韧—脆性剪切带的改造,容矿沉积岩在多期、多阶段活动下表现为片理化(近EW向)和破碎控矿构造带(近EW-NE向交会),构造带中花岗岩脉形成蚀变岩石,产生的含矿热液形成扁豆体—透镜体状及脉状矿体,就位于控矿韧—脆性构造带中。热液成矿具有多期、多阶段作用特征,矿化具有自形、半自形微细浸染结构构造特征,载金矿物为含砷黄铁矿、毒砂和硅化石英,含少量辉锑矿,显示Au-As-Hg-Sb地球化学组合特征。     

陕西铧厂沟金矿床地质特征及成矿规律

铧厂沟金矿床位于秦岭褶皱系南部,北距康县—略阳—勉县深大断裂4 km。金矿化严格受地层、岩性及韧性剪切带控制,主要控矿层位为蚀变细碧岩及灰岩与粉砂质千枚岩之间的过渡部位,控矿构造多为压扭性断裂。金矿体呈脉状和透镜状产出,矿化带类型以蚀变细碧岩型及蚀变碳酸盐岩型为主,黄铁矿是矿石中最主要的载金矿物。矿石中金的赋存状态主要为包裹金和裂隙金,粒间金次之,围岩蚀变主要有黄铁矿化、硅化、碳酸盐化、钠长石化和绢云母化等。黄铁矿热电系数和原生晕地球化学研究显示,本区金矿体向深部有一定的延伸,应重点加强细碧岩型矿带和砂岩矿带的地质找矿与探矿工作。     

内蒙古奈林沟金矿床C-H-O同位素地球化学特征

为了查明奈林沟金矿床的成矿物质来源及矿床成因,分别对氢、氧同位素和碳、氧同位素进行了测试分析。石英流体包裹体氢、氧同位素研究表明:δ18O变化范围在-3.6‰~0.2‰,平均值为-1.71‰,石英的δD介于-115‰~-98‰,平均值为-105.9‰,说明成矿流体与岩浆作用关系密切,原始岩浆水是早期成矿流体主要来源,后期则有大量的大气降水混入,是岩浆水与大气降水共同组成的混合水。方解石的碳、氧同位素研究表明:δ13C平均值为-4.54‰,与地幔δ13C值-5.5‰相近;δ18O平均值为7.86‰,与花岗岩δ18O的变化范围7‰~13‰相符,说明成矿流体与花岗岩质岩浆热液有关。综合分析认为,奈林沟金矿床属于浅成中低温重熔岩浆热液型金矿床。     

青海省阿哈大洼金多金属矿床地质特征及矿床成因

阿哈大洼金多金属矿床位于青海省柴达木盆地北缘地区,该区地质环境复杂,成矿条件优越。目前已在该矿区发现金矿(化)体2条,银、铅、铜矿(化)体各1条。本次调查研究的重点是对区域成矿地质背景、矿区和矿床地质特征进行分析研究,进而探讨矿床成因。研究表明,北西—近东西向断裂构造控制着区内矿(化)体产状、形态及规模,加里东—印支期岩浆活动为本区成矿提供了热源与矿源物质。综合分析认为,阿哈大洼金多金属矿床为造山型金矿床。     

陕西潼峪剪切带型金矿类型及特征

潼峪地区发育一系列韧性剪切带构造，金矿床严格受这些真心性剪切带的控制，主要矿床类型可分为石英脉型、构造（蚀变）岩型。     

陕西小燕子沟金矿床流体包裹体特征及成矿物理化学条件研究

小燕子沟金矿为近些年在川陕甘金三角地区发现的一处中小型金矿床,产在一大型韧性剪切带中,围岩为碧口群地层。矿体严格受断裂控制,按照矿石自然类型,可进一步划分为石英脉型与蚀变岩型。流体包裹体以气液二相包裹体为主,还有部分纯液相包裹体。显微测温结果显示,气液二相包裹体的均一温度峰值为180～300℃,盐度w（NaCl）峰值为2%～5%,密度峰值为0.80～0.95 g/cm3,具有中温、低盐度、低密度的特征。估算成矿压力为50～80 MPa,成矿深度约为5.5～7.5 km。据盐-温图成矿流体的盐度随着温度下降而升高,在180～220℃温度区间内,原始流体发生了减压沸腾,导致矿质卸载沉淀。     

Dissolved rare earth elements estimation of ion-absorption rare earth ores using reflectance spectroscopy in south Jiangxi province,China

Ion-absorption rare earth ores are an important mineral resource in China. Nowadays, the unauthorized mining has become a serious problem, resulting in severe water pollution and the wastage of rare earth elements (REEs). Being able to estimate the concentration of dissolved REEs in water bodies near mines is essential for tackling this environmental problem. Conventionally, quantitative analyses of the contents of dissolved REEs are performed using laboratory-based techniques, which can be time consuming and costly. Spectral reflectance is a rapid and cost-effective means of characterizing the chemical compositions of light-absorbing materials. In this study, reflectance spectroscopy was performed on dissolved REEs, and the correlation between their reflectance characteristics and REE content was determined. A total of 50 aqueous media samples collected in south Jiangxi Province and 25 laboratory-produced aqueous media samples were tested, and their reflectance spectra and REE contents were measured using reflectance spectroscopy and inductively coupled plasma mass spectrometry, respectively. Next, the reflectance, differential reflectance, and absorption depth were analysed based on the REE content. Six diagnostic absorption features related to REEs are recognised in the visible and near-infrared wavelength regions, along with several smaller peaks. It indicates that the results of the absorption depth analysis are in accordance with the absorption spectra characteristics of the REEs, with the R² value being higher than 0.97. The intensity of each of the six absorption bands exhibits a linear correlation to the total REE content. Therefore, linear regression models can be derived for estimating the total concentration of REEs in aqueous media samples. What's more, the detection limit for REEs is determined to be about 30 μg/L. Thus, it can be concluded that reflectance spectroscopy is a suitable technique for estimating the concentration of dissolved REEs.     

湖北大悟大坡顶金矿床微量元素地球化学特征

以湖北大悟大坡项矿区内不同类型（岩）矿石的元素分析数据为基础,从多元统计的角度,对微量元素地球化学特征进行了表征。该矿床的矿石可分为石英脉型和蚀变岩型。通过对矿,石及围岩的微量元素组成及其与金的相关性的多元统计分析,将微量元素划分为3种组合类型,即：①As、Sb;②Au、Ag、Cu、Pb、Zn;③Mo。第一组合为成矿头晕组合;第二组合为矿体元素组合;第三组合为尾晕组合。     

陕西龙头沟金矿地质特征及找矿方向

龙头沟金矿是近年发现的构造蚀变岩型金矿,产于泥盆系砂岩中,成因类型为受构造控制的中温岩浆热液矿床。在介绍区域地质特征的基础上,总结与成矿有关的主要控矿条件,指出矿体主要受近EW向断裂控制,断裂倾向与地层相反,并且围岩岩性、蚀变强弱和矿体产出标高均对矿体的形态和品位有不同程度的影响。结合近年外围工作进展,提出本地区今后找矿勘查工作应围绕走向剪切断裂、区内矿化蚀变带及外围化探异常开展,同时对背斜南翼开展找矿勘查工作。     

Distribution of rare earth elements in sewage-irrigated soil profiles in Tianjin, China

The concentrations of rare earth elements(REEs)in the soil extracts and soil solutions from two different alluvial soil profiles irrigated with sewage were measured using inductively coupled plasma-mass spectrometry.The results showed that the REE concentrations in the soil extracts from soil samples affected by sewage irrigation were much higher than those in virgin soil samples.The REE concentrations in the soil extracts of the rhizophere soil were higher than those of the non-rhizophere soil.The shale-normalized REE patterns in the soil extracts from the upper soil layer affected by sewage irrigation shown middle REE(MREE)enrichment relative to light REE(LREE)and heavy REE(HREE).This result was attributed to the MREE-rich organic colloidal material,REE-HM(humic and fulvic acids)and phosphate-REE complexations.The REE patterns in the soil extracts from deep soil little-affected by sewage irrigation showed HREE enrichment relative to LREE,which might have been caused by the preferential complexation of HREE with carbonate.The normalized La/Yb ratios in the soil extracts increased with the decrease in depth.The sewage irrigation did not affect the total REE contents and REE pattern in the soil profiles.     

陕西凤县庞家河－左家庄地区金矿伴生元素特征及其地质意义

伴生元素特征研究是金矿研究的重要内容之一，是间接找矿的重要手段，也是金矿床评价的重要依据。本文以庞家河金矿为主，对庞家河－左家庄地区诸金矿床（点）伴生元素特征进行系统归纳和总结，并阐述其意义，从而对该地区金矿床成因研究、金矿找矿勘探及矿床评价提供依据。     

甘肃小金滩金矿床地质特征及控矿因素

小金滩金矿床位于南秦岭多金属成矿带的谈家庄—广金坝印支—燕山期金锑汞成矿亚带内。在分析成矿环境的基础上,总结了矿床的地质特征,探讨了矿床的控矿因素。研究表明,金矿床受断裂带中主构造特定部位及次级构造控制,并与火山喷发作用、中酸性岩浆侵入以及深部成矿流体的多期次活动带来的多种热液蚀变的强烈叠加作用关系密切。     

四川省九寨沟草地金矿床地质特征及矿床成因

四川草地金矿床为位于若尔盖—九寨沟印支—燕山期金矿成矿带内的超微细粒浸染型金矿床。通过对该矿床的地质特征、矿石矿物学特征以及控矿因素的系统研究表明,该矿床受构造断裂带控制,在时空上与印支—燕山期岩浆侵入活动密切相关。容矿岩石主要为古生界泥盆系、石炭系构造角砾岩和蚀变花岗斑岩。矿体主要呈脉状、透镜状、浸染状产出。矿床地球化学研究结果表明,成矿物质主要来源于围岩和深部地壳,属低温热液型金矿床。     

电感耦合等离子体质谱法测定砂金中稀土元素

建立了砂金中15种稀土元素的电感耦合等离子体质谱测定方法。考察了基体Au的谱线干扰及基体效应,采用In内标补偿基体对待测信号的抑制作用。仪器检测限为0.000 9～0.002 9μg/L,加入标准物质的回收率为98%～106.7%,分析结果的相对标准偏差（RSD）为0.33%～1.79%。该方法简单、快速、灵敏、准确。     

云南镇沅老王寨金矿床地质特征及成因探讨

作为哀牢山金矿带北段的典型矿床,老王寨金矿床空间上位于北西向脆韧性剪切带与东西向逆冲脆韧性剪切带交汇部位,北西向脆韧性剪切带、不同时代的中酸性浅成侵入体、基性和超基性岩侵入体以及哀牢山群变质岩系与金矿体具有密切的时空及成因联系。矿石中石英的流体包裹体分析表明,金矿的成矿流体主要为中低温、低盐度的NaCl-H2O体系。结合同位素、成岩成矿年代的研究认为,成矿物质及成矿流体均主要来自深部的上地幔或下地壳,金的大规模成矿与喜山期深部岩浆作用密切相关。